The present invention is drawn to a process for the direct reduction of metal oxides containing iron to a metallized iron product.
The direct reduction of iron oxide, in forms such as pellets or lump ore, to metallic iron in the solid state has become a commercial reality throughout the world in recent years. The combined annual capacity of direct reduction plants currently in operation or under construction is in excess of 15 million metric tons of direct reduced iron product, which is used primarily for feedstock in electric arc steelmaking furnaces. The world demand for additional direct reduced iron is projected to increase at a substantial rate for many years to satisfy a growing world need for such feedstock, as additional electric arc furnace steelmaking plants are constructed.
Known processes for the direct reduction of iron oxide to metallic iron utilize a reformed gas as the reducing agent. Natural gas is used as a source for generating the reformed gas. The reformed gas for use in the direct reduction process is generated in a unit called a reformer by contacting the natural gas with an oxygen containing material in the presence of a catalyst, usually a nickel catalyst, which activates the reformation reaction of the natural gas so as to yield a reformed gas which is rich in H.sub.2 and CO. The reformed gas which is collected from the reformer is thereafter fed to a reduction reactor containing the iron oxide material wherein the direct reduction reaction is carried out. Thus, direct reduction processes heretofore known require two distinct reaction zones for carrying out the actual direct reduction process. In these conventional processes it is required that the reformed gas product in the first zone be treated prior to entering the reduction zone in order to remove CO.sub.2 and/or water vapor.
Naturally, it would be highly desirable to provide a method for the direct reduction of iron oxide materials to metallic iron which would eliminate the necessity of separate reaction zones and the use of nickel catalysts.
Accordingly, it is the principal object of the present invention to provide an improved process for the direct reduction of metal oxides containing iron to a metallized iron product.
It is a particular object of the present invention to provide a method as set forth above which is carried out in the single reaction zone of a direct reduction reactor.
It is a further object of the present invention to provide a method as set forth above wherein DRI material is used as a catalyst to produce a reformed gas directly in the reaction zone of a direct reduction reactor.
It is still further object of the present invention to provide an apparatus for carrying out the method of the present invention.
Further objects and advantages of the present invention will appear hereinbelow.